void main(){

  //常用属性
  Map person = {
    "name":"张三",
    "sex":"男",
    "age":20
  };

  //获取value和key
  print(person.keys.toList());
  print(person.values.toList());
  //判空
  print(person.isEmpty);
  print(person.isNotEmpty);

  //常用方法
  //addAll()
  person.addAll({
    "work":["程序员","送外卖"],
    "height":168
  });
  print(person);

  //remove()
  person.remove("sex");
  print(person);

  //查找映射
  print(person.containsKey("work"));
  print(person.containsValue("20"));
  
}